Once upon a time there was Charlotte ... Granddaughter of Louis-Philippe, beloved child of Leopold I, cousin of Queen Victoria, Archduchess of Austria by her marriage in 1857 to Maximilian of Habsburg, Empress of Mexico at 24 years old. so many titles and ties of kinship which foreshadowed a golden existence for this beautiful princess. However, the magical destiny that was promised to him soon turned into tragedy. In this essay, in the light of the most recent historical and psychiatric research, we propose to retrace the plunge into darkness of the madness of Charlotte of Belgium (1840-1927).